New metallomacrocyclic complexes based on acetamidrazone

The reaction of the linear polyether dialdehyde 3,3′-(3,6-dioxaoctane-1,8-diyldioxy)-bis(2-hydroxybenzaldehyde) (1) with acetamidrazone hydrochloride in the presence of barium triflate, followed by addition of metal(II) acetate, where metal(II)=nickel(II), copper(II) or zinc(II), yields dimeric heterometallic complexes [NiBaL(CF3SO3)2]2 (2), [CuBaL(CF3SO3)2]2 (4) and [ZnBaL(CF3SO3)2(CH3OH)]2 (6), where H2L=macrocyclic ligand. Removal of Ba2+ from 2, 4 and 6 by using an aqueous solution of guanidinium sulfate affords NiL·2H2O (3), CuL·1.5H2O (5) and ZnL·2H2O (7). The crystal structure of 2 has been determined by X-ray diffraction methods. The X-ray diffraction powder patterns show that 4 is isostructural with 2. Electronic, EI, MALDI/TOF and ESI mass, NMR and ESR spectra are reported. Thermal degradation of 3, 5 and 7 gives pure metal(II) oxides.